Construction And Characterization Of Recombinant Tagged Foot And Mouth Disease Virus Of Asial

Reverse-genetic engineering of foot and mouth disease virus (FMDV) can improve the productivity,antigen matching, antigen stability, immune response ability, and biological safety of vaccines, so vaccinecandidates with anticipated biological characteristics can be promptly achieved. Negative influence intaming of virulent strains can also be decreased or avoided. Reverse genetics not only make up fordeficiencies like limitation of viral nature, low success rate, and time and energy consuming, but alsorealize more active designing of vaccines. Therefore, reverse genetics is significant in improving integralquality and efficiency of vaccines.To identify a feasible insertion site in the foot-and-mouth disease virus (FMDV) and obtain a taggedrecombinant virus, in this study, we have used reverse genetics to introduce His tag into the ninth site in thedownstream of RGD motif in FMDV and obtain a histidine(His)-tagged full-length-cDNA clone namedprAsiaI-9His. We transfected the prAsiaI-9His into BHK-21cells and typical cytopathic effect (CPE) wereobserve in the transfacted BHK-21cells. Then, we used RT-PCR, indirect immunofluorescence assay andsequence analysis, the results showed that the recombinant virus named as rAsiaI-9His successfully rescuedand the His tag was stably maintained. Finally, we compared rAsiaI-9His with the parental virus namedrAsiaI for pathogenicity to BHK-21cells and suckling mouse, the results showed they had similar TCID50and LD50.Though the Tagged virus rAsiaI-9His pathogenicity tests showed that the recombinant FMDV could bepathogenic for cattle produce clinical symptoms.The structual proteins and non-structual protein antibodyresponse analysis showed that the wild-type virus rAsia1and recombinant virus are similar. The results oftagged virus rAsiaI-9His for serum neutralization test calculated that the r values are about1.0. The resultsshowed that tagged virus and epidemic isolates has good matching in antigencity.The tagged FMDV lays afoundation for further study of molecular pathogenesis and marker vaccine of FMDV.In short, the insertion of His tag not only provides a tool for the research of the molecular mechanismof FMDV, but aslo provides a higher lever of purification way for the traditional vaccine production.It playsa most important role in distinguishing between vaccinated and infection animals of FMDV.